The present invention relates in general to panic exit type latching devices for doors and the like, and, more particularly, to a novel concealed rod, panic exit door latching system having a latch bolt push-bar actuator for a three point locking system and a high-security combination lock interlinked therewith.
A number of panic exit or panic egress lock hardware has been developed, to provide for exit from school classrooms, auditoriums, theaters and the like, wherein an elongated push plate serving as a panic bar is supported for rectilinear movement toward and away from the adjacent surface of the door for activating a main latch bolt, or a pair of top and bottom latch bolts, or both the vertical edge and top and bottom latch bolts. Such panic exit devices are designed to be automatically released by a relatively small force and relatively slight movement applied to the panic bar from the inside of the building to facilitate actuation of the panic bar and unlocking of the door upon application of pressure toward the surface of the door upon which the panic exit device is mounted. Typically, such panic exit devices include a primary latch bolt mounted in the vertical free edge of the door at approximately the level of the panic exit device and a pair of secondary latch bolts at the top and at the bottom of the door, all operated from the panic bar. Usually, a main center case is provided having bell crank mechanisms interconnecting a rectilinearly reciprocating control link activated by a panic bar for operating the top and bottom latches by control rods connected from the bell crank members to such latches while the primary or center latch bolt is operated directly from the main control link. Examples of such panic exit devices are found in earlier U.S. patents such as U.S. Pat. Nos. 3,563,585 to Welch, 3,582,122 to Foster, 3,788,687, 3,767,238 to Zawadzki, 4,427,223 to Godec et al, 4,601,499 to Kim, and 4,741,563 to Cohrs as typical of this type of panic exit device.
Previous designs of the panic exit device have usually used a solid linkage between the main control link and the secondary outputs of the center case mechanism operating the top and bottom latch bolts. Thus when the secondary outputs were depressed, the main control link was retracted which in turn retracted the latch bolts of the panic exit device. In a two or three point latching system, defeat of any one of the latches in the system allowed unauthorized entry.
Such panic exit systems are also frequently used in security areas, wherein the panic exit device with its push bar release mechanism permits egress, while a remote access control system, such as a push button or card controlled access system or a key cylinder lock permits activation of the panic exit device from the exterior to retract the latch bolts.
The device of the present invention was developed to fulfill a need for a panic egress device which works in conjunction with a high security lock, such as a high security combination lock. From the outside of the door secured by the panic exit lock system, both the high security lock and the panic exit device must operate independently of each other. From the egress or inner side of the door, depressing the push pad or panic bar must retract both the bolts in the panic exit device and the bolt in the high security lock. This allows the device to meet both panic and high security requirements. Many applications exist where both the high security and panic exit or panic egress requirements are needed. Currently, the way in which these requirements are met is through the use of two door for a given room. One door is used for the panic exit requirement, with the door being provided with a panic exit device mounted on the inside with no means of entry from the outside. This door always remains locked from the outside. The other door uses a high security lock as a means for passage from the outside of the door to the inside. The present invention is designed to eliminate the need for two doors where both high security and panic egress requirements are needed, and which permits operation of the panic exit lock mechanism to retract the primary latch bolt responsive to and outside key or outside activation of a remote control access system without retracting the high security lock, and which provides that the primary latch bolt in the panic exit device will not retract when the high security lock is retracted. In other words, both the panic exit device and the high security lock must be unlatched independently of each other to gain entry from the outside. However, depressing the push pad or panic bar on the device retracts both the high security lock and bolt and the latch bolts of the panic device to permit egress.
An object of the present invention, therefor, is the provision of a novel high security exit lock system, including a mechanically operated panic exit lock device and a high security combination lock interlinked therewith, wherein unlocking and bolt retraction of the panic exit device and the high security combination lock are achieved independently without retraction of the primary latch bolt or the combination lock bolt effecting retraction of the other, so that both the panic exit device and the high security lock must be unlatched independently to gain entry from outside of the building.
Another object of the present invention is the provision of a high security exit device as described in the immediately preceding paragraph, wherein lost motion is provided between the main control link of the panic exit device and the bolt retracting mechanism of the combination lock whereby opening of the combination lock does not transfer opening movement to the main control link of the panic exit device and opening movement of the main control link of the panic exit device does not apply opening movement to the bolt retracting components of the combination lock.
Another object of the present invention is the provision of a novel high security exit device of the type described in the two immediately preceding paragraph, wherein a two or three point latching system involving two or three latching bolts respectively are provided in the panic exit device and the lock bolt of the combination lock is sufficiently independent of the mechanism for retracting the panic exit device bolts so that defeat of a panic exit device bolt and the combination lock bolt must be attained simultaneously to gain unauthorized entry.
Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawing illustrating a preferred embodiment of the invention.